The present invention relates to a specific structure for the front part of a vehicle frame.
As taught by Japanese Patent Laid-Open No. 6-278646, there is an automotive vehicle frame design in which the front part of the vehicle frame is comprised of an extension frame positioned so as to extend in the forward direction from the front end of vehicle's side frame member. The side frame member is aligned longitudinally with the vehicle's fore-aft axis, and its front part is inclined downward in the area where the aforesaid extension frame is installed. The upper surface of the extension frame is of an approximate flat configuration, and the entire extension frame itself extends forward and upward in relation to the downward inclination of the side frame member. When a heavy impact load is applied to the extension frame, it progressively collapses in a manner whereby the distortion begins at the forward-most part of the extension frame and proceeds toward the rear. The collapsing structure eventually assumes a V-shape as it approaches its energy-absorbing limit. In order to increases the extension frame's energy absorbing capacity, it is comprised of two overlapping. U-shaped components called the extension frame inner and extension frame outer which, when assembled, form a closed cross sectional area.
The extension frame inner and outer components are connected to the outer surfaces on the end of the side frame member, and also to the first cross member which meets the side frame member in the lateral direction in relation to the vehicle's fore-aft axis. A gusset piece is installed over the upper surface of the extension frame, and also to the side frame and cross member, with the purpose of increasing the strength of the extension frame.